v4.19.13 snapshot.
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
new file mode 100644
index 0000000..3a6c8eb
--- /dev/null
+++ b/arch/x86/tools/relocs.c
@@ -0,0 +1,1106 @@
+// SPDX-License-Identifier: GPL-2.0
+/* This is included from relocs_32/64.c */
+
+#define ElfW(type) _ElfW(ELF_BITS, type)
+#define _ElfW(bits, type) __ElfW(bits, type)
+#define __ElfW(bits, type) Elf##bits##_##type
+
+#define Elf_Addr ElfW(Addr)
+#define Elf_Ehdr ElfW(Ehdr)
+#define Elf_Phdr ElfW(Phdr)
+#define Elf_Shdr ElfW(Shdr)
+#define Elf_Sym ElfW(Sym)
+
+static Elf_Ehdr ehdr;
+
+struct relocs {
+ uint32_t *offset;
+ unsigned long count;
+ unsigned long size;
+};
+
+static struct relocs relocs16;
+static struct relocs relocs32;
+#if ELF_BITS == 64
+static struct relocs relocs32neg;
+static struct relocs relocs64;
+#endif
+
+struct section {
+ Elf_Shdr shdr;
+ struct section *link;
+ Elf_Sym *symtab;
+ Elf_Rel *reltab;
+ char *strtab;
+};
+static struct section *secs;
+
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
+/*
+ * Following symbols have been audited. There values are constant and do
+ * not change if bzImage is loaded at a different physical address than
+ * the address for which it has been compiled. Don't warn user about
+ * absolute relocations present w.r.t these symbols.
+ */
+ [S_ABS] =
+ "^(xen_irq_disable_direct_reloc$|"
+ "xen_save_fl_direct_reloc$|"
+ "VDSO|"
+ "__crc_)",
+
+/*
+ * These symbols are known to be relative, even if the linker marks them
+ * as absolute (typically defined outside any section in the linker script.)
+ */
+ [S_REL] =
+ "^(__init_(begin|end)|"
+ "__x86_cpu_dev_(start|end)|"
+ "(__parainstructions|__alt_instructions)(|_end)|"
+ "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
+ "__(start|end)_pci_.*|"
+ "__(start|end)_builtin_fw|"
+ "__(start|stop)___ksymtab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
+ "__(start|stop)___kcrctab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
+ "__(start|stop)___param|"
+ "__(start|stop)___modver|"
+ "__(start|stop)___bug_table|"
+ "__tracedata_(start|end)|"
+ "__(start|stop)_notes|"
+ "__end_rodata|"
+ "__end_rodata_aligned|"
+ "__initramfs_start|"
+ "(jiffies|jiffies_64)|"
+#if ELF_BITS == 64
+ "__per_cpu_load|"
+ "init_per_cpu__.*|"
+ "__end_rodata_hpage_align|"
+#endif
+ "__vvar_page|"
+ "_end)$"
+};
+
+
+static const char * const sym_regex_realmode[S_NSYMTYPES] = {
+/*
+ * These symbols are known to be relative, even if the linker marks them
+ * as absolute (typically defined outside any section in the linker script.)
+ */
+ [S_REL] =
+ "^pa_",
+
+/*
+ * These are 16-bit segment symbols when compiling 16-bit code.
+ */
+ [S_SEG] =
+ "^real_mode_seg$",
+
+/*
+ * These are offsets belonging to segments, as opposed to linear addresses,
+ * when compiling 16-bit code.
+ */
+ [S_LIN] =
+ "^pa_",
+};
+
+static const char * const *sym_regex;
+
+static regex_t sym_regex_c[S_NSYMTYPES];
+static int is_reloc(enum symtype type, const char *sym_name)
+{
+ return sym_regex[type] &&
+ !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
+}
+
+static void regex_init(int use_real_mode)
+{
+ char errbuf[128];
+ int err;
+ int i;
+
+ if (use_real_mode)
+ sym_regex = sym_regex_realmode;
+ else
+ sym_regex = sym_regex_kernel;
+
+ for (i = 0; i < S_NSYMTYPES; i++) {
+ if (!sym_regex[i])
+ continue;
+
+ err = regcomp(&sym_regex_c[i], sym_regex[i],
+ REG_EXTENDED|REG_NOSUB);
+
+ if (err) {
+ regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
+ die("%s", errbuf);
+ }
+ }
+}
+
+static const char *sym_type(unsigned type)
+{
+ static const char *type_name[] = {
+#define SYM_TYPE(X) [X] = #X
+ SYM_TYPE(STT_NOTYPE),
+ SYM_TYPE(STT_OBJECT),
+ SYM_TYPE(STT_FUNC),
+ SYM_TYPE(STT_SECTION),
+ SYM_TYPE(STT_FILE),
+ SYM_TYPE(STT_COMMON),
+ SYM_TYPE(STT_TLS),
+#undef SYM_TYPE
+ };
+ const char *name = "unknown sym type name";
+ if (type < ARRAY_SIZE(type_name)) {
+ name = type_name[type];
+ }
+ return name;
+}
+
+static const char *sym_bind(unsigned bind)
+{
+ static const char *bind_name[] = {
+#define SYM_BIND(X) [X] = #X
+ SYM_BIND(STB_LOCAL),
+ SYM_BIND(STB_GLOBAL),
+ SYM_BIND(STB_WEAK),
+#undef SYM_BIND
+ };
+ const char *name = "unknown sym bind name";
+ if (bind < ARRAY_SIZE(bind_name)) {
+ name = bind_name[bind];
+ }
+ return name;
+}
+
+static const char *sym_visibility(unsigned visibility)
+{
+ static const char *visibility_name[] = {
+#define SYM_VISIBILITY(X) [X] = #X
+ SYM_VISIBILITY(STV_DEFAULT),
+ SYM_VISIBILITY(STV_INTERNAL),
+ SYM_VISIBILITY(STV_HIDDEN),
+ SYM_VISIBILITY(STV_PROTECTED),
+#undef SYM_VISIBILITY
+ };
+ const char *name = "unknown sym visibility name";
+ if (visibility < ARRAY_SIZE(visibility_name)) {
+ name = visibility_name[visibility];
+ }
+ return name;
+}
+
+static const char *rel_type(unsigned type)
+{
+ static const char *type_name[] = {
+#define REL_TYPE(X) [X] = #X
+#if ELF_BITS == 64
+ REL_TYPE(R_X86_64_NONE),
+ REL_TYPE(R_X86_64_64),
+ REL_TYPE(R_X86_64_PC32),
+ REL_TYPE(R_X86_64_GOT32),
+ REL_TYPE(R_X86_64_PLT32),
+ REL_TYPE(R_X86_64_COPY),
+ REL_TYPE(R_X86_64_GLOB_DAT),
+ REL_TYPE(R_X86_64_JUMP_SLOT),
+ REL_TYPE(R_X86_64_RELATIVE),
+ REL_TYPE(R_X86_64_GOTPCREL),
+ REL_TYPE(R_X86_64_32),
+ REL_TYPE(R_X86_64_32S),
+ REL_TYPE(R_X86_64_16),
+ REL_TYPE(R_X86_64_PC16),
+ REL_TYPE(R_X86_64_8),
+ REL_TYPE(R_X86_64_PC8),
+#else
+ REL_TYPE(R_386_NONE),
+ REL_TYPE(R_386_32),
+ REL_TYPE(R_386_PC32),
+ REL_TYPE(R_386_GOT32),
+ REL_TYPE(R_386_PLT32),
+ REL_TYPE(R_386_COPY),
+ REL_TYPE(R_386_GLOB_DAT),
+ REL_TYPE(R_386_JMP_SLOT),
+ REL_TYPE(R_386_RELATIVE),
+ REL_TYPE(R_386_GOTOFF),
+ REL_TYPE(R_386_GOTPC),
+ REL_TYPE(R_386_8),
+ REL_TYPE(R_386_PC8),
+ REL_TYPE(R_386_16),
+ REL_TYPE(R_386_PC16),
+#endif
+#undef REL_TYPE
+ };
+ const char *name = "unknown type rel type name";
+ if (type < ARRAY_SIZE(type_name) && type_name[type]) {
+ name = type_name[type];
+ }
+ return name;
+}
+
+static const char *sec_name(unsigned shndx)
+{
+ const char *sec_strtab;
+ const char *name;
+ sec_strtab = secs[ehdr.e_shstrndx].strtab;
+ name = "<noname>";
+ if (shndx < ehdr.e_shnum) {
+ name = sec_strtab + secs[shndx].shdr.sh_name;
+ }
+ else if (shndx == SHN_ABS) {
+ name = "ABSOLUTE";
+ }
+ else if (shndx == SHN_COMMON) {
+ name = "COMMON";
+ }
+ return name;
+}
+
+static const char *sym_name(const char *sym_strtab, Elf_Sym *sym)
+{
+ const char *name;
+ name = "<noname>";
+ if (sym->st_name) {
+ name = sym_strtab + sym->st_name;
+ }
+ else {
+ name = sec_name(sym->st_shndx);
+ }
+ return name;
+}
+
+static Elf_Sym *sym_lookup(const char *symname)
+{
+ int i;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ long nsyms;
+ char *strtab;
+ Elf_Sym *symtab;
+ Elf_Sym *sym;
+
+ if (sec->shdr.sh_type != SHT_SYMTAB)
+ continue;
+
+ nsyms = sec->shdr.sh_size/sizeof(Elf_Sym);
+ symtab = sec->symtab;
+ strtab = sec->link->strtab;
+
+ for (sym = symtab; --nsyms >= 0; sym++) {
+ if (!sym->st_name)
+ continue;
+ if (strcmp(symname, strtab + sym->st_name) == 0)
+ return sym;
+ }
+ }
+ return 0;
+}
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define le16_to_cpu(val) (val)
+#define le32_to_cpu(val) (val)
+#define le64_to_cpu(val) (val)
+#endif
+#if BYTE_ORDER == BIG_ENDIAN
+#define le16_to_cpu(val) bswap_16(val)
+#define le32_to_cpu(val) bswap_32(val)
+#define le64_to_cpu(val) bswap_64(val)
+#endif
+
+static uint16_t elf16_to_cpu(uint16_t val)
+{
+ return le16_to_cpu(val);
+}
+
+static uint32_t elf32_to_cpu(uint32_t val)
+{
+ return le32_to_cpu(val);
+}
+
+#define elf_half_to_cpu(x) elf16_to_cpu(x)
+#define elf_word_to_cpu(x) elf32_to_cpu(x)
+
+#if ELF_BITS == 64
+static uint64_t elf64_to_cpu(uint64_t val)
+{
+ return le64_to_cpu(val);
+}
+#define elf_addr_to_cpu(x) elf64_to_cpu(x)
+#define elf_off_to_cpu(x) elf64_to_cpu(x)
+#define elf_xword_to_cpu(x) elf64_to_cpu(x)
+#else
+#define elf_addr_to_cpu(x) elf32_to_cpu(x)
+#define elf_off_to_cpu(x) elf32_to_cpu(x)
+#define elf_xword_to_cpu(x) elf32_to_cpu(x)
+#endif
+
+static void read_ehdr(FILE *fp)
+{
+ if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
+ die("Cannot read ELF header: %s\n",
+ strerror(errno));
+ }
+ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
+ die("No ELF magic\n");
+ }
+ if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) {
+ die("Not a %d bit executable\n", ELF_BITS);
+ }
+ if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
+ die("Not a LSB ELF executable\n");
+ }
+ if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
+ die("Unknown ELF version\n");
+ }
+ /* Convert the fields to native endian */
+ ehdr.e_type = elf_half_to_cpu(ehdr.e_type);
+ ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine);
+ ehdr.e_version = elf_word_to_cpu(ehdr.e_version);
+ ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry);
+ ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff);
+ ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff);
+ ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags);
+ ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize);
+ ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize);
+ ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum);
+ ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize);
+ ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
+ ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx);
+
+ if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
+ die("Unsupported ELF header type\n");
+ }
+ if (ehdr.e_machine != ELF_MACHINE) {
+ die("Not for %s\n", ELF_MACHINE_NAME);
+ }
+ if (ehdr.e_version != EV_CURRENT) {
+ die("Unknown ELF version\n");
+ }
+ if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) {
+ die("Bad Elf header size\n");
+ }
+ if (ehdr.e_phentsize != sizeof(Elf_Phdr)) {
+ die("Bad program header entry\n");
+ }
+ if (ehdr.e_shentsize != sizeof(Elf_Shdr)) {
+ die("Bad section header entry\n");
+ }
+ if (ehdr.e_shstrndx >= ehdr.e_shnum) {
+ die("String table index out of bounds\n");
+ }
+}
+
+static void read_shdrs(FILE *fp)
+{
+ int i;
+ Elf_Shdr shdr;
+
+ secs = calloc(ehdr.e_shnum, sizeof(struct section));
+ if (!secs) {
+ die("Unable to allocate %d section headers\n",
+ ehdr.e_shnum);
+ }
+ if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
+ die("Seek to %d failed: %s\n",
+ ehdr.e_shoff, strerror(errno));
+ }
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (fread(&shdr, sizeof shdr, 1, fp) != 1)
+ die("Cannot read ELF section headers %d/%d: %s\n",
+ i, ehdr.e_shnum, strerror(errno));
+ sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
+ sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
+ sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
+ sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr);
+ sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset);
+ sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size);
+ sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link);
+ sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
+ sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
+ sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
+ if (sec->shdr.sh_link < ehdr.e_shnum)
+ sec->link = &secs[sec->shdr.sh_link];
+ }
+
+}
+
+static void read_strtabs(FILE *fp)
+{
+ int i;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_STRTAB) {
+ continue;
+ }
+ sec->strtab = malloc(sec->shdr.sh_size);
+ if (!sec->strtab) {
+ die("malloc of %d bytes for strtab failed\n",
+ sec->shdr.sh_size);
+ }
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
+ die("Seek to %d failed: %s\n",
+ sec->shdr.sh_offset, strerror(errno));
+ }
+ if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
+ die("Cannot read symbol table: %s\n",
+ strerror(errno));
+ }
+ }
+}
+
+static void read_symtabs(FILE *fp)
+{
+ int i,j;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_SYMTAB) {
+ continue;
+ }
+ sec->symtab = malloc(sec->shdr.sh_size);
+ if (!sec->symtab) {
+ die("malloc of %d bytes for symtab failed\n",
+ sec->shdr.sh_size);
+ }
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
+ die("Seek to %d failed: %s\n",
+ sec->shdr.sh_offset, strerror(errno));
+ }
+ if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
+ die("Cannot read symbol table: %s\n",
+ strerror(errno));
+ }
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) {
+ Elf_Sym *sym = &sec->symtab[j];
+ sym->st_name = elf_word_to_cpu(sym->st_name);
+ sym->st_value = elf_addr_to_cpu(sym->st_value);
+ sym->st_size = elf_xword_to_cpu(sym->st_size);
+ sym->st_shndx = elf_half_to_cpu(sym->st_shndx);
+ }
+ }
+}
+
+
+static void read_relocs(FILE *fp)
+{
+ int i,j;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
+ continue;
+ }
+ sec->reltab = malloc(sec->shdr.sh_size);
+ if (!sec->reltab) {
+ die("malloc of %d bytes for relocs failed\n",
+ sec->shdr.sh_size);
+ }
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
+ die("Seek to %d failed: %s\n",
+ sec->shdr.sh_offset, strerror(errno));
+ }
+ if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
+ die("Cannot read symbol table: %s\n",
+ strerror(errno));
+ }
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+ rel->r_offset = elf_addr_to_cpu(rel->r_offset);
+ rel->r_info = elf_xword_to_cpu(rel->r_info);
+#if (SHT_REL_TYPE == SHT_RELA)
+ rel->r_addend = elf_xword_to_cpu(rel->r_addend);
+#endif
+ }
+ }
+}
+
+
+static void print_absolute_symbols(void)
+{
+ int i;
+ const char *format;
+
+ if (ELF_BITS == 64)
+ format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n";
+ else
+ format = "%5d %08"PRIx32" %5"PRId32" %10s %10s %12s %s\n";
+
+ printf("Absolute symbols\n");
+ printf(" Num: Value Size Type Bind Visibility Name\n");
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ char *sym_strtab;
+ int j;
+
+ if (sec->shdr.sh_type != SHT_SYMTAB) {
+ continue;
+ }
+ sym_strtab = sec->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) {
+ Elf_Sym *sym;
+ const char *name;
+ sym = &sec->symtab[j];
+ name = sym_name(sym_strtab, sym);
+ if (sym->st_shndx != SHN_ABS) {
+ continue;
+ }
+ printf(format,
+ j, sym->st_value, sym->st_size,
+ sym_type(ELF_ST_TYPE(sym->st_info)),
+ sym_bind(ELF_ST_BIND(sym->st_info)),
+ sym_visibility(ELF_ST_VISIBILITY(sym->st_other)),
+ name);
+ }
+ }
+ printf("\n");
+}
+
+static void print_absolute_relocs(void)
+{
+ int i, printed = 0;
+ const char *format;
+
+ if (ELF_BITS == 64)
+ format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64" %s\n";
+ else
+ format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32" %s\n";
+
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ struct section *sec_applies, *sec_symtab;
+ char *sym_strtab;
+ Elf_Sym *sh_symtab;
+ int j;
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
+ continue;
+ }
+ sec_symtab = sec->link;
+ sec_applies = &secs[sec->shdr.sh_info];
+ if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
+ continue;
+ }
+ sh_symtab = sec_symtab->symtab;
+ sym_strtab = sec_symtab->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel;
+ Elf_Sym *sym;
+ const char *name;
+ rel = &sec->reltab[j];
+ sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
+ name = sym_name(sym_strtab, sym);
+ if (sym->st_shndx != SHN_ABS) {
+ continue;
+ }
+
+ /* Absolute symbols are not relocated if bzImage is
+ * loaded at a non-compiled address. Display a warning
+ * to user at compile time about the absolute
+ * relocations present.
+ *
+ * User need to audit the code to make sure
+ * some symbols which should have been section
+ * relative have not become absolute because of some
+ * linker optimization or wrong programming usage.
+ *
+ * Before warning check if this absolute symbol
+ * relocation is harmless.
+ */
+ if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
+ continue;
+
+ if (!printed) {
+ printf("WARNING: Absolute relocations"
+ " present\n");
+ printf("Offset Info Type Sym.Value "
+ "Sym.Name\n");
+ printed = 1;
+ }
+
+ printf(format,
+ rel->r_offset,
+ rel->r_info,
+ rel_type(ELF_R_TYPE(rel->r_info)),
+ sym->st_value,
+ name);
+ }
+ }
+
+ if (printed)
+ printf("\n");
+}
+
+static void add_reloc(struct relocs *r, uint32_t offset)
+{
+ if (r->count == r->size) {
+ unsigned long newsize = r->size + 50000;
+ void *mem = realloc(r->offset, newsize * sizeof(r->offset[0]));
+
+ if (!mem)
+ die("realloc of %ld entries for relocs failed\n",
+ newsize);
+ r->offset = mem;
+ r->size = newsize;
+ }
+ r->offset[r->count++] = offset;
+}
+
+static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
+ Elf_Sym *sym, const char *symname))
+{
+ int i;
+ /* Walk through the relocations */
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ char *sym_strtab;
+ Elf_Sym *sh_symtab;
+ struct section *sec_applies, *sec_symtab;
+ int j;
+ struct section *sec = &secs[i];
+
+ if (sec->shdr.sh_type != SHT_REL_TYPE) {
+ continue;
+ }
+ sec_symtab = sec->link;
+ sec_applies = &secs[sec->shdr.sh_info];
+ if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
+ continue;
+ }
+ sh_symtab = sec_symtab->symtab;
+ sym_strtab = sec_symtab->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+ Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
+ const char *symname = sym_name(sym_strtab, sym);
+
+ process(sec, rel, sym, symname);
+ }
+ }
+}
+
+/*
+ * The .data..percpu section is a special case for x86_64 SMP kernels.
+ * It is used to initialize the actual per_cpu areas and to provide
+ * definitions for the per_cpu variables that correspond to their offsets
+ * within the percpu area. Since the values of all of the symbols need
+ * to be offsets from the start of the per_cpu area the virtual address
+ * (sh_addr) of .data..percpu is 0 in SMP kernels.
+ *
+ * This means that:
+ *
+ * Relocations that reference symbols in the per_cpu area do not
+ * need further relocation (since the value is an offset relative
+ * to the start of the per_cpu area that does not change).
+ *
+ * Relocations that apply to the per_cpu area need to have their
+ * offset adjusted by by the value of __per_cpu_load to make them
+ * point to the correct place in the loaded image (because the
+ * virtual address of .data..percpu is 0).
+ *
+ * For non SMP kernels .data..percpu is linked as part of the normal
+ * kernel data and does not require special treatment.
+ *
+ */
+static int per_cpu_shndx = -1;
+static Elf_Addr per_cpu_load_addr;
+
+static void percpu_init(void)
+{
+ int i;
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ ElfW(Sym) *sym;
+ if (strcmp(sec_name(i), ".data..percpu"))
+ continue;
+
+ if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */
+ return;
+
+ sym = sym_lookup("__per_cpu_load");
+ if (!sym)
+ die("can't find __per_cpu_load\n");
+
+ per_cpu_shndx = i;
+ per_cpu_load_addr = sym->st_value;
+ return;
+ }
+}
+
+#if ELF_BITS == 64
+
+/*
+ * Check to see if a symbol lies in the .data..percpu section.
+ *
+ * The linker incorrectly associates some symbols with the
+ * .data..percpu section so we also need to check the symbol
+ * name to make sure that we classify the symbol correctly.
+ *
+ * The GNU linker incorrectly associates:
+ * __init_begin
+ * __per_cpu_load
+ *
+ * The "gold" linker incorrectly associates:
+ * init_per_cpu__irq_stack_union
+ * init_per_cpu__gdt_page
+ */
+static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
+{
+ return (sym->st_shndx == per_cpu_shndx) &&
+ strcmp(symname, "__init_begin") &&
+ strcmp(symname, "__per_cpu_load") &&
+ strncmp(symname, "init_per_cpu_", 13);
+}
+
+
+static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
+ const char *symname)
+{
+ unsigned r_type = ELF64_R_TYPE(rel->r_info);
+ ElfW(Addr) offset = rel->r_offset;
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ if (sym->st_shndx == SHN_UNDEF)
+ return 0;
+
+ /*
+ * Adjust the offset if this reloc applies to the percpu section.
+ */
+ if (sec->shdr.sh_info == per_cpu_shndx)
+ offset += per_cpu_load_addr;
+
+ switch (r_type) {
+ case R_X86_64_NONE:
+ /* NONE can be ignored. */
+ break;
+
+ case R_X86_64_PC32:
+ case R_X86_64_PLT32:
+ /*
+ * PC relative relocations don't need to be adjusted unless
+ * referencing a percpu symbol.
+ *
+ * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
+ */
+ if (is_percpu_sym(sym, symname))
+ add_reloc(&relocs32neg, offset);
+ break;
+
+ case R_X86_64_32:
+ case R_X86_64_32S:
+ case R_X86_64_64:
+ /*
+ * References to the percpu area don't need to be adjusted.
+ */
+ if (is_percpu_sym(sym, symname))
+ break;
+
+ if (shn_abs) {
+ /*
+ * Whitelisted absolute symbols do not require
+ * relocation.
+ */
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ die("Invalid absolute %s relocation: %s\n",
+ rel_type(r_type), symname);
+ break;
+ }
+
+ /*
+ * Relocation offsets for 64 bit kernels are output
+ * as 32 bits and sign extended back to 64 bits when
+ * the relocations are processed.
+ * Make sure that the offset will fit.
+ */
+ if ((int32_t)offset != (int64_t)offset)
+ die("Relocation offset doesn't fit in 32 bits\n");
+
+ if (r_type == R_X86_64_64)
+ add_reloc(&relocs64, offset);
+ else
+ add_reloc(&relocs32, offset);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ }
+
+ return 0;
+}
+
+#else
+
+static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
+ const char *symname)
+{
+ unsigned r_type = ELF32_R_TYPE(rel->r_info);
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ switch (r_type) {
+ case R_386_NONE:
+ case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
+ /*
+ * NONE can be ignored and PC relative relocations don't
+ * need to be adjusted.
+ */
+ break;
+
+ case R_386_32:
+ if (shn_abs) {
+ /*
+ * Whitelisted absolute symbols do not require
+ * relocation.
+ */
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ die("Invalid absolute %s relocation: %s\n",
+ rel_type(r_type), symname);
+ break;
+ }
+
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ }
+
+ return 0;
+}
+
+static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
+ const char *symname)
+{
+ unsigned r_type = ELF32_R_TYPE(rel->r_info);
+ int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
+ switch (r_type) {
+ case R_386_NONE:
+ case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
+ /*
+ * NONE can be ignored and PC relative relocations don't
+ * need to be adjusted.
+ */
+ break;
+
+ case R_386_16:
+ if (shn_abs) {
+ /*
+ * Whitelisted absolute symbols do not require
+ * relocation.
+ */
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ if (is_reloc(S_SEG, symname)) {
+ add_reloc(&relocs16, rel->r_offset);
+ break;
+ }
+ } else {
+ if (!is_reloc(S_LIN, symname))
+ break;
+ }
+ die("Invalid %s %s relocation: %s\n",
+ shn_abs ? "absolute" : "relative",
+ rel_type(r_type), symname);
+ break;
+
+ case R_386_32:
+ if (shn_abs) {
+ /*
+ * Whitelisted absolute symbols do not require
+ * relocation.
+ */
+ if (is_reloc(S_ABS, symname))
+ break;
+
+ if (is_reloc(S_REL, symname)) {
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+ }
+ } else {
+ if (is_reloc(S_LIN, symname))
+ add_reloc(&relocs32, rel->r_offset);
+ break;
+ }
+ die("Invalid %s %s relocation: %s\n",
+ shn_abs ? "absolute" : "relative",
+ rel_type(r_type), symname);
+ break;
+
+ default:
+ die("Unsupported relocation type: %s (%d)\n",
+ rel_type(r_type), r_type);
+ break;
+ }
+
+ return 0;
+}
+
+#endif
+
+static int cmp_relocs(const void *va, const void *vb)
+{
+ const uint32_t *a, *b;
+ a = va; b = vb;
+ return (*a == *b)? 0 : (*a > *b)? 1 : -1;
+}
+
+static void sort_relocs(struct relocs *r)
+{
+ qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
+}
+
+static int write32(uint32_t v, FILE *f)
+{
+ unsigned char buf[4];
+
+ put_unaligned_le32(v, buf);
+ return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
+}
+
+static int write32_as_text(uint32_t v, FILE *f)
+{
+ return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1;
+}
+
+static void emit_relocs(int as_text, int use_real_mode)
+{
+ int i;
+ int (*write_reloc)(uint32_t, FILE *) = write32;
+ int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
+ const char *symname);
+
+#if ELF_BITS == 64
+ if (!use_real_mode)
+ do_reloc = do_reloc64;
+ else
+ die("--realmode not valid for a 64-bit ELF file");
+#else
+ if (!use_real_mode)
+ do_reloc = do_reloc32;
+ else
+ do_reloc = do_reloc_real;
+#endif
+
+ /* Collect up the relocations */
+ walk_relocs(do_reloc);
+
+ if (relocs16.count && !use_real_mode)
+ die("Segment relocations found but --realmode not specified\n");
+
+ /* Order the relocations for more efficient processing */
+ sort_relocs(&relocs32);
+#if ELF_BITS == 64
+ sort_relocs(&relocs32neg);
+ sort_relocs(&relocs64);
+#else
+ sort_relocs(&relocs16);
+#endif
+
+ /* Print the relocations */
+ if (as_text) {
+ /* Print the relocations in a form suitable that
+ * gas will like.
+ */
+ printf(".section \".data.reloc\",\"a\"\n");
+ printf(".balign 4\n");
+ write_reloc = write32_as_text;
+ }
+
+ if (use_real_mode) {
+ write_reloc(relocs16.count, stdout);
+ for (i = 0; i < relocs16.count; i++)
+ write_reloc(relocs16.offset[i], stdout);
+
+ write_reloc(relocs32.count, stdout);
+ for (i = 0; i < relocs32.count; i++)
+ write_reloc(relocs32.offset[i], stdout);
+ } else {
+#if ELF_BITS == 64
+ /* Print a stop */
+ write_reloc(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < relocs64.count; i++)
+ write_reloc(relocs64.offset[i], stdout);
+
+ /* Print a stop */
+ write_reloc(0, stdout);
+
+ /* Now print each inverse 32-bit relocation */
+ for (i = 0; i < relocs32neg.count; i++)
+ write_reloc(relocs32neg.offset[i], stdout);
+#endif
+
+ /* Print a stop */
+ write_reloc(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < relocs32.count; i++)
+ write_reloc(relocs32.offset[i], stdout);
+ }
+}
+
+/*
+ * As an aid to debugging problems with different linkers
+ * print summary information about the relocs.
+ * Since different linkers tend to emit the sections in
+ * different orders we use the section names in the output.
+ */
+static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
+ const char *symname)
+{
+ printf("%s\t%s\t%s\t%s\n",
+ sec_name(sec->shdr.sh_info),
+ rel_type(ELF_R_TYPE(rel->r_info)),
+ symname,
+ sec_name(sym->st_shndx));
+ return 0;
+}
+
+static void print_reloc_info(void)
+{
+ printf("reloc section\treloc type\tsymbol\tsymbol section\n");
+ walk_relocs(do_reloc_info);
+}
+
+#if ELF_BITS == 64
+# define process process_64
+#else
+# define process process_32
+#endif
+
+void process(FILE *fp, int use_real_mode, int as_text,
+ int show_absolute_syms, int show_absolute_relocs,
+ int show_reloc_info)
+{
+ regex_init(use_real_mode);
+ read_ehdr(fp);
+ read_shdrs(fp);
+ read_strtabs(fp);
+ read_symtabs(fp);
+ read_relocs(fp);
+ if (ELF_BITS == 64)
+ percpu_init();
+ if (show_absolute_syms) {
+ print_absolute_symbols();
+ return;
+ }
+ if (show_absolute_relocs) {
+ print_absolute_relocs();
+ return;
+ }
+ if (show_reloc_info) {
+ print_reloc_info();
+ return;
+ }
+ emit_relocs(as_text, use_real_mode);
+}